Aluminum Sulfate Treatment for Iowa Lakes

The Iowa Department of Natural Resources is seeking bids for the aluminum sulfate treatment of Lake of Three Fires, Green Valley Lake, and Prairie Rose Lake. The treatment aims to mitigate the internal release of phosphorus from sediments. The contractor will be responsible for mobilizing and demobilizing labor, equipment, and materials, applying liquid aluminum sulfate and sodium aluminate, and restoring disturbed areas. The project is expected to be completed in two phases: fall 2025 and spring 2026. • The contractor must provide a detailed work plan, including contractor contact information, spill prevention and contingency plans, and application details. • The contractor must ensure that commercial-grade liquid aluminum sulfate and sodium aluminate are evenly and simultaneously applied to the lake. • The contractor must monitor the ambient pH in the lake hourly during the aluminum treatment application and stop treatment if the pH falls below 6.5 or increases above 8.5 S.U. • The contractor must keep daily records of the treatment, including hours of chemical application, quantity of chemical applied, pH logs, and chemical data sheets.